Controlling the stability and the electronic structure of transition metal dichalcogenide single layer under chemical doping

Abstract

By means of ab initio calculation based on density-functional theory (DFT), we have investigated the electronic and optical properties of single layer MoSe2 under chemical doping by various groups, such as -H, -OH, -NH2 and -CH3. This work is generalized for all polymorph 1H, 1T, 1T' and the new investigated phase 1T ''. We found that all those functional groups (FG) bonded covalently to the chalcogen atom (Se). The evaluation of adsorption energy shows that the hydrogen atom binds more strongly than other functional groups in particular with the T phase. Furthermore, the attachment of functional groups to T-MoSe2 leads to dramatic changes to the structure stability and the optoelectronic properties of the material by tuning its band gap from metallic to a semiconductor. Also, we found that the band gap is strongly depending on the type and the densities of dopants. (C) 2019 Elsevier B.V. All rights reserved.